1. Field of the Invention
This invention concerns itself with an active agent that is suitable for treating chronic obstructive pulmonary disease (COPD). The present agents may be administered preventatively, prophylactically or therapeutically in conjunction with other therapies, or may be utilized as a substitute for therapies that have significant, negative side effects.
2. Description of the Background
Chronic obstructive pulmonary disease (COPD) causes a continuing obstruction of airflow in the airways. COPD is characterized by airflow obstruction that is generally caused by chronic bronchitis, emphysema, or both. Commonly, the airway obstruction is mostly irreversible. In chronic bronchitis, airway obstruction results from chronic and excessive secretion of abnormal airway mucus, inflammation, bronchospasm, and infection. Chronic bronchitis is also characterized by chronic cough, mucus production, or both, for at least three months in at least two successive years where other causes of chronic cough have been excluded. In emphysema, a structural element (elastin) in the terminal bronchioles is destroyed leading to the collapse of the airway walls and inability to exhale “stale” air. In emphysema there is permanent destruction of the alveoli. Emphysema is characterized by abnormal permanent enlargement of the air spaces distal to the terminal bronchioles, accompanied by destruction of their walls and without obvious fibrosis. COPD can also give rise to secondary pulmonary hypertension. Secondary pulmonary hypertension itself is a disorder in which blood pressure in the pulmonary arteries is abnormally high. In severe cases, the right side of the heart must work harder than usual to pump blood against the high pressure. If this continues for a long period, the right heart enlarges and functions poorly, and fluid collects in the ankles (edema) and belly. Eventually the left heart begins to fail. Heart failure caused by pulmonary disease is called cor pulmonale.
COPD characteristically affects middle aged and elderly people, and is one of the leading causes of morbidity and mortality worldwide. In the United States it affects about 14 million people and is the fourth leading cause of death, and the third leading cause for disability in the United States. Both morbidity and mortality, however, are rising. The estimated prevalence of this disease in the United States has risen by 41% since 1982, and age adjusted death rates rose by 71% between 1966 and 1985. This contrasts with the decline over the same period in age-adjusted mortality from all causes (which fell by 22%), and from cardiovascular diseases (which fell by 45%). In 1998 COPD accounted for 112,584 deaths in the United States.
COPD, however, is preventable, since it is believed that its main cause is exposure to cigarette smoke. Long-term smoking is the most frequent cause of COPD. It accounts for 80 to 90% of all cases. A smoker is 10 times more likely than a non-smoker to die of COPD. The disease is rare in lifetime non-smokers, in whom exposure to environmental tobacco smoke will explain at least some of the airways obstruction. Other proposed etiological factors include airway hyper responsiveness or hypersensitivity, ambient air pollution, and allergy. The airflow obstruction in COPD is usually progressive in people who continue to smoke. This results in early disability and shortened survival time. Stopping smoking reverts the decline in lung function to values for non-smokers. Other risk factors include: heredity, second-hand smoke, exposure to air pollution at work and in the environment, and a history of childhood respiratory infections. The symptoms of COPD include: chronic coughing, chest tightness, shortness of breath, an increased effort to breathe, increased mucus production, and frequent clearing of the throat.
There is very little currently available to alleviate symptoms of COPD, prevent exacerbations, preserve optimal lung function, and improve daily living activities and quality of life. Many patients will use medication chronically for the rest of their lives, with the need for increased doses and additional drugs during exacerbations. Medications that are currently prescribed for COPD patients include: fast-acting β2-agonists, anticholinergic bronchodilators, long-acting bronchodilators, antibiotics, and expectorants. Amongst the currently available treatments for COPD, short term benefits, but not long term effects, were found on its progression, from administration of anti-cholinergic drugs, β2 adrenergic agonists, and oral steroids.
Short and long acting inhaled β2 adrenergic agonists achieve short-term bronchodilation and provide some symptomatic relief in COPD patients, but show no meaningful maintenance effect on the progression of the disease. Short acting β2 adrenergic agonists improve symptoms in subjects with COPD, such as increasing exercise capacity and produce some degree of bronchodilation, and even an increase in lung function in some severe cases. The maximum effectiveness of the newer long acting inhaled, β2 adrenergic agonists was found to be comparable to that of short acting β2 adrenergic agonists. Salmeterol was found to improve symptoms and quality of life, although only producing modest or no change in lung function. In asthmatics, however, β2 adrenergic agonists have been linked to an increased risk of death, worsened control of asthma, and deterioration in lung function. β2-agonists, such as albuterol, help to open narrowed airways. The use of β2-agonists can produce paradoxical bronchospasm, which may be life threatening to the COPD patient. In addition, the use of β2-agonists can produce cardiovascular effects, such as altered pulse rate, blood pressure and electrocardiogram results. In rare cases, the use of β2-agonists can produce hypersensitivity reactions, such as urticaria, angioedema, rash and oropharyngeal edema. In these cases, the use of the β2-agonist should be discontinued. Continuous treatment of asthmatic and COPD patients with the bronchodilators ipratropium bromide or fenoterol resulted in a faster decline in lung function, when compared with treatment provided on a need basis, therefore indicating that they are not suitable for maintenance treatment. The most common immediate adverse effect of β2 adrenergic agonists, on the other hand, is tremors, which at high doses may cause a fall in plasma potassium, dysrhythmias, and reduced arterial oxygen tension. The combination of a β2 adrenergic agonist with an anti-cholinergic drug provides little additional bronchodilation compared with either drug alone. The addition of ipratropium to a standard dose of inhaled β2 adrenergic agonists for about 90 days, however, produces some improvement in stable COPD patients over either drug alone. Anti-cholinergic agents were found to produce greater bronchodilation in combination with anti-cholinergic agents than β2 adrenergic agonists, in people with COPD. Overall, the occurrence of adverse effects with β2 adrenergic agonists, such as tremor and dysrhythmias, is more frequent than with anti-cholinergics. Thus, neither anti-cholinergic drugs nor β2 adrenergic agonists have an effect on all people with COPD; nor do the two agents combined.
Anti-cholinergic drugs achieve short-term bronchodilation and produce some symptom relief in people with COPD, but no improved long-term prognosis even with inhaled products. Most COPD patients have at least some measure of airways obstruction that is somewhat alleviated by ipratropium bromide. “The lung health study” found in men and women smokers spirometric signs of early COPD. Three treatments compared over a five year period found that ipratropium bromide had no significant effect on the decline in the functional effective volume of the patient's lungs whereas smoking cessation produced a slowing of the decline in the functional effective volume of the lungs. Ipratropium bromide, however, produced serious adverse effects, such as cardiac symptoms, hypertension, skin rashes, and urinary retention. Anticholinergic bronchodilators, such as ipratropium bromide, and theophylline derivatives, help to open narrowed airways. Long-acting bronchodilators help to relieve constriction of the airways and help prevent bronchospasm associated with COPD. Theophyllines have a small bronchodilatory effect in COPD patients whereas they have some common adverse effects, and they have a small therapeutic range given that blood concentrations of 15-20 mg/l are required for optimal effects. Adverse effects include nausea, diarrhea, headache, irritability, seizures, and cardiac arrhythmias, and they occur at highly variable blood concentrations and, in many people, they occur within the therapeutic range. The theophyllines' doses must be adjusted individually according to smoking habits, infection, and other treatments, which is cumbersome. Although theophyllines have been claimed to have an anti-inflammatory effect in asthma, especially at lower doses, none has been reported in COPD, although their bronchodilating short-term effect appears to be statistically different from placebo. The adverse effects of theophyllines and the need for frequent monitoring limit their usefulness. There is no evidence that anti-cholinergic agents affect the decline in lung function, and mucolytics have been shown to reduce the frequency of exacerbations but with a possible deleterious effect on lung function. The long-term effects of β2 adrenergic agonists, oral corticosteroids, and antibiotics have not yet been evaluated, and up to the present time no other drug has been shown to affect the progression of the disease or survival.
Oral corticosteroids elicit some improvement in baseline functional effective volume in stable COPD patients whereas systemic corticosteroids have been found to be harmful at least producing some osteoporosis and inducing overt diabetes. The longer term administration of oral corticosteroids may be useful in COPD, but their usefulness must be weighed against their substantial adverse effects. Inhaled corticosteroids have been found to have no real short-term effect on airway hyper-responsiveness to histamine, but a small long-term effect on lung function, e.g., in pre-bronchodilator functional effective volume. Fluticasone treatment of COPD patients showed a significant reduction in moderate and severe (but not mild) exacerbations, and a small but significant improvement in lung function and six minute walking distance. Oral prednisolone, inhaled beclomethasone or both had no effects in COPD patients, but lung function improved oral corticosteroids. Mucolytics have a modest beneficial effect on the frequency and duration of exacerbations but an adverse effect on lung function. Neither N-acetylcysteine nor other mucolytics, however, have a significant effect in people with severe COPD (functional effective volume<50%) in spite of evidencing greater reductions in frequency of exacerbation. N-acetylcysteine produced gastrointestinal side effect. Long-term oxygen therapy administered to hypoxaemic COPD and congestive cardiac failure, patients, had little effect on their rates of death for the first 500 days or so, but survival rates in men increased afterwards and remained constant over the next five years. In women, however, oxygen decreased the rates of death throughout the study. Continuous oxygen treatment of hypoxemic COPD patients (functional effective volume<70% predicted) for 19.3 years decreased overall risk of death. To date, however, only life style changes, smoking cessation and long term treatment with oxygen (in hypoxaemics), have been found to alter the long-term course of COPD.
Antibiotics are also often given at the first sign of a respiratory infection to prevent further damage and infection in diseased lungs. Expectorants help loosen and expel mucus secretions from the airways, and may help make breathing easier.
In addition, other medications may be prescribed to manage conditions associated with COPD. These may include: diuretics (which are given as therapy to avoid excess water retention associated right-heart failure), digitalis (which strengthens the force of the heartbeat), painkillers cough suppressants, and sleeping pills. This latter list of medications help alleviate symptoms associated with COPD but do not treat COPD.
Thus, there is very little currently available to alleviate symptoms of COPD, prevent exacerbations, preserve optimal lung function, and improve daily living activities an quality of life.
COPD and other respiratory ailments, associated with a variety of diseases and conditions, are extremely common in the general population, and more so in certain ethnic groups, such as African Americans. In some cases they are accompanied by inflammation, which aggravates the condition of the lungs. Asthma, for example, is one of the most common diseases in industrialized countries. In the United States it accounts for about 1% of all health care costs. An alarming increase in both the prevalence and mortality of asthma over the past decade has been reported, and asthma is predicted to be the preeminent occupational lung disease in the next decade. While the increasing mortality of asthma in industrialized countries could be attributable to the reliance upon beta agonists in the treatment of this disease, the underlying causes of asthma remain poorly understood.
Other respiratory diseases such as asthma, allergic rhinitis, and Acute Respiratory Distress Syndrome (ARDS), including ARDS in pregnant mothers and Respiratory Distress Syndrome (RDS) in premature born infants, pulmonary fibrosis, and cystic fibrosis (CF), among others, are common diseases in industrialized countries, and in the United States alone account for extremely high health care costs. These diseases have recently been increasing at an alarming rate, both in terms of prevalence, morbidity and mortality. In spite of this, their underlying causes still remain poorly understood.
Asthma is a condition characterized by variable, in many instances reversible obstruction of the airways. This process is associated with lung inflammation and in some cases lung allergies. Many patients have acute episodes referred to as “asthma attacks,” while others are afflicted with a chronic condition. The asthmatic process is believed to be triggered in some cases by inhalation of antigens by hypersensitive subjects. This condition is generally referred to as “extrinsic asthma.” Other asthmatics have an intrinsic predisposition to the condition, which is thus referred to as “instrinsic asthma,” and may be comprised of conditions of different origin, including those mediated by the adenosine receptor(s), allergic conditions mediated by an immune IgE-mediated response, and others. All asthmas have a group of symptoms, which are characteristic of this condition: bronchoconstriction, lung inflammation and decreased lung surfactant. Existing bronchodilators and anti-inflammatories are currently commercially available and are prescribed for the treatment of asthma. The most common anti-inflammatories, corticosteroids, have considerable side effects but are commonly prescribed nevertheless. Most of the drugs available for the treatment of asthma are, more importantly, barely effective in a small number of patients. Acute Respiratory Distress Syndrome (ARDS) is also known in the medical literature as stiff lung, shock lung, pump lung and congestive atelectasis, and its incidence is 1 out of 100,000 people. ARDS is believed to be caused by a failure of the respiratory system characterized by fluid accumulation within the lung that, in turn, causes the lung to stiffen. The condition is triggered by a variety of processes that injure the lungs. In general, ARDS occurs as a medical emergency. It may be caused by a variety of conditions that directly or indirectly cause the blood vessels to “leak” fluid into the lungs. In ARDS, the ability of the lungs to expand is severely decreased and damage to the air sacs and lining (endothelium) of the lung is extensive. The concentration of oxygen in the blood remains very low in spite of high concentration of supplemental oxygen that is generally administered to a patient. Among the systemic causes of lung injury are trauma, head injury, shock, sepsis, multiple blood transfusions and medications. Pulmonary causes include pulmonary embolism, severe pneumonia, smoke inhalation, radiation, high altitude, near drowning, and others like cigarette smoking. ARDS symptoms usually develop within 24 to 48 hours of the occurrence of an injury or illness.
ARDS′ most common symptoms are labored, rapid breathing, nasal flaring, cyanosis blue skin, lips and nails caused by lack of oxygen to the tissues, breathing difficulty, anxiety, stress, tension, joint stiffness, pain and temporarily absent breathing. ARDS is commonly diagnosed by testing for symptomatic signs, for example by a simple chest auscultation or examination with a stethoscope that may reveal abnormal symptomatic breath sounds. A preliminary diagnosis of ARDS may be confirmed with chest X-rays and the measurement of arterial blood gas. In some cases ARDS appears to be associated with other diseases, such as acute myelogenous leukemia, with acute tumor lysis syndrome (ATLS) developed after treatment with, e.g. cytosine arabinoside. In general, however, ARDS appears to be associated with traumatic injury, severe blood infections such as sepsis, or other systemic illness, high dose radiation therapy and chemotherapy, and inflammatory responses which lead to multiple organ failure, and in many cases death. In premature babies (“premies”), the lungs are not quite developed and, therefore, the fetus is in an anoxic state during development. Moreover, lung surfactant, a material critical for normal respiration, is generally not yet present in sufficient amounts at this early stage of life; however, premies often hyper-express the adenosine A, receptor and/or underexpress the adenosine A2a receptor and are, therefore, susceptible to respiratory problems including bronchoconstriction, lung inflammation and ARDS, among others. When Respiratory Distress Syndrome (RDS) occurs in premies, it is an extremely serious problem. Preterm infants exhibiting RDS are currently treated by ventilation and administration of oxygen and surfactant preparations. When premies survive RDS, they frequently develop bronchopulmonary dysplasia (BPD), also called chronic lung disease of early infancy, which is often fatal.
The systemic administration of adenosine was found useful for treating SVT, and as a pharmacologic means to evaluate cardiovascular health via an adenosine stress test commonly administered by hospitals and by doctors in private practice. Adenosine administered by inhalation, however, is known to cause bronchoconstriction in asthmatics, possibly due to mast cell degranulation and histamine release, effects which have not been observed in normal subjects. Adenosine infusion has caused respiratory compromise, for example, in patients with COPD. As a consequence of the untoward side effects observed in many patients, caution is recommended in the prescription of adenosine to patients with a variety of conditions, including obstructive lung disease, emphysema, bronchitis, etc, and complete avoidance of its administration to patients with or prone to bronchoconstriction or bronchospasm, such as asthma. In addition, the administration of adenosine must be discontinued in any patient who develops severe respiratory difficulties. It would be of great help if a formulation were to be made available for joint use when adenosine administration is required.
Rhinitis may be seasonal or perennial, allergic or non-allergic. Non-allergic rhinitis may be induced by infections, such as viruses, or associated with nasal polyps, as occurs in patients with aspirin idiosyncrasy. Medical conditions such as pregnancy or hypothyroidism and exposure to occupational factors or medications may cause rhinitis. Allergic rhinitis afflicts one in five Americans, accounting for an estimated $4 to 10 billion in health care costs each year, and occurs at all ages. Because many people mislabel their symptoms as persistent colds or sinus problems, allergic rhinitis is probably underdiagnosed. Typically, IgE combines with allergens in the nose to produce release of chemical mediators, induction of cellular processes, and neurogenic stimulation, causing an underlying inflammation. Symptoms include nasal congestion, discharge, sneezing, and itching, as well as itchy, watery, swollen eyes. Over time, allergic rhinitis sufferers often develop sinusitis, otitis media with effusion, and nasal polyposis, and may exacerbate asthma, and is associated with mood and cognitive disturbances, fatigue and irritability. When cholinergic pathways are stimulated they produce typical secretions that are identified by their glandular constituents so as to implicate neurologic stimulation. Other secretions typical of increased vascular permeability are found in allergic reactions as well as upper respiratory infections, and degranulation of mast cells results in the release of preformed mediators that interact with various cells, blood vessels, and mucous glands to produce the typical rhinitis symptoms. Most early- and late-phase reactions occur in the nose after allergen exposure. The late-phase reaction is seen in chronic allergic rhinitis, with hypersecretion and congestion as the most prominent symptoms. Repeated exposure causes a hypersensitivity reaction to one or many allergens. Sufferers may also become hyperreactive to nonspecific triggers such as cold air or strong odors. Nonallergic rhinitis may be induced by infections, such as viruses, or associated with nasal polyps, as occurs in patients with aspirin idiosyncrasy. In addition, pregnancy, hypothyroidism, and exposure to occupational factors or medications can cause rhinitis, as well. NARES syndrome, a non-allergic type of rhinitis associated with eosinophils in the nasal secretions, typically occurs in middle-aged individuals and is accompanied by loss of smell. Saline is often recommended to improve nasal stuffiness, sneezing, and congestion, and saline sprays usually relieve mucosal irritation or dryness associated with various nasal conditions, minimize mucosal atrophy, and dislodge encrusted or thickened mucus, while causing no side effects, and may be tried first in pregnant patients. Also, if used immediately before intranasal corticosteroid dosing, saline helps prevent local irritation. Anti-histamines often serve as a primary therapy. Terfenadine and astemizole, two non-sedating anti-histamines, however, have been associated with a ventricular arrhythmia known as Torsades de Points, usually in interaction with other medications such as ketoconazole and erythromycin, or secondary to an underlying cardiac problem. To date loratadine, another nonsedating anti-histamine, and cetirizine have not been associated with serious adverse cardiovascular events, the most common side effect of cetirizine being drowsiness. Claritin, for example, may be effective in relieving sneezing, runny nose, and nasal, ocular and palatal itching in a low percentage of patients, although not approved for this indication or asthma. Terfenadine, loratadine and astemizole, on the other hand, exhibit extremely modest bronchodilating effects, reduction of bronchial hyper-reactivity to histamine, and protection against exercise- and antigen-induced bronchospasm. Some of these benefits, however, require higher-than-currently-recommended doses. The sedating-type anti-histamines help induce night sleep, but they cause sleepiness and compromise performance if taken during the day. Anti-histamines are typically combined with a decongestant to help relieve nasal congestion. Sympathomimetic medications are used as vasoconstrictors and decongestants, the three most common decongestants being pseudoephedrine, phenylpropanolamine and phenylephrine. These agents, however, cause hypertension, palpitations, tachycardia, restlessness, insomnia and headache. The interaction of phenylpropanolamine with caffeine, in doses of two to three cups of coffee, may significantly raise blood pressure. In addition, medications such as pseudoephedrine may cause hyperactivity in children. Topical decongestants are recommended for a limited period of time, as their over use results in nasal dilatation. Anti-cholinergic agents, such as Cromolyn, have a role in patients with significant rhinorrhea or for specific entities such as “gustatory rhinitis”, which is usually associated with ingestion of spicy foods, and have been used on the common cold. However, sometimes the Cromolyn spray produces sneezing, transient headache, and even nasal burning. Topical and nasal spray corticosteroids such as Vancenase are effective agents in the treatment of rhinitis, especially for symptoms of congestion, sneezing, and runny nose, but often cause irritation, stinging, burning, sneezing, local bleeding and septal perforation. Topical steroids are generally more effective than Cromolyn Sodium, particularly in the treatment of NARES, but side effects limit their usefulness except for temporary therapy in patients with severe symptoms. These agents are sometimes used for shrinking nasal polyps when local therapy fails. Immunotherapy, while expensive and inconvenient, often can provide substantial benefits, especially the use of drugs that produce blocking antibodies, alter cellular histamine release, and result in decreased IgE. Presently available treatments, such as propranolol, verapamil, and adenosine (all of which have FDA-approved labeling for acute termination of supraventricular tachycardia (SVT)), may help to minimize symptoms. Verapamil is most commonly used but it has several shortcomings, since it causes or exacerbates systemic hypotension, congestive heart failure, bradyarrhythmias, and ventricular fibrillation. In addition, verapamil readily crosses the placenta and has been shown to cause fetal bradycardia, heart block, depression of contractility, and hypotension. Adenosine has several advantages over verapamil, including rapid onset, brevity of side effects, theoretical safety, and probable lack of placental transfer, but may not be administered to a variety of patients.
Pulmonary fibrosis, interstitial lung disease (ILD), or interstitial pulmonary fibrosis, include more than 130 chronic lung disorders that affect the lung by damaging lung tissue, and producing inflammation in the walls of the air sacs in the lung, scarring or fibrosis in the interstitium (or tissue between the air sacs), and stiffening of the lung, thus the name of the disease. Although the progress and symptoms of pulmonary fibrosis and other ILDs may vary from person to person, they have one common link: they affect parts of the lung. When inflammation involves the walls of the bronchioles (small airways), it is called bronchiolitis, when it involves the walls and air spaces of the alveoli (air sacs), it is called alveolitis, and when it involves the small blood vessels (capillaries) of the lungs, it is called vasculitis. The inflammation may heal, or it may lead to permanent scarring of the lung tissue, in which case it is called pulmonary fibrosis. This fibrosis or scarring of the lung tissue results in permanent loss of its ability to breathe and carry oxygen, and the amount of scarring determines the level of disability a person experiences because of the destruction by the scar tissue of the air sacs and lung tissue between and surrounding the air sacs and the lung capillaries. When this happens, oxygen is generally administered to help improve breathing. Pulmonary fibrosis is caused by, or takes the form of, occupational and environmental exposure to irritants such as asbestos, silica and metal dusts, bacteria and animal dusts, gases and fumes, asbestosis and silicosis, infections that produce lung scarring, of which tuberculosis is one example, connective tissue or collagen diseases such as Rheumatoid Arthritis, Systemic Sclerosis and Systemic Lupus Erythematosis, idiopathic pulmonary fibrosis and, although not as common, pulmonary fibrosis of genetic/familial origin and certain medicines. Many of the diseases are often named after the occupations with which they are associated, such as Grain handlier's lung, Mushroom worker's lung, Bagassosis, Detergent worker's lung, Maple bark stripper's lung, Malt worker's lung, Paprika splitter's lung, and Bird breeder's lung. “Idiopathic” (of unknown origin) pulmonary fibrosis (IPF) is the label applied when all other causes of interstitial lung disease have been ruled out, and is said to be caused by viral illness and allergic or environmental exposure (including tobacco smoke). Bacteria and other microorganisms are not thought to be a cause of IPF. There is also a familial form of the disease, known as familial idiopathic pulmonary fibrosis whose main symptom is shortness of breath. Since many lung diseases show this symptom, making a correct diagnosis is often difficult. The shortness of breath may first appear during exercise and the condition may progress then to the point where any exertion is impossible. Eventually resulting in shortness of breath even at rest. Other symptoms may include a dry cough (without sputum), and clubbing of the fingertips. Glucocorticosteroids are usually administered to treat inflammation present in pulmonary fibrosis, with inconclusive results. Other drugs, however, are not usually added until it is clear that the steroids are not effective in reversing the disease. Glucocorticosteroids are also used in combination with other drugs when a diagnosis is first established, for example oxygen therapy prescribed in severe cases. The administration of influenza and pneumococcal pneumonia vaccines is often recommended in pulmonary fibrosis and more generally for all lung diseases to prevent infection. The treatment and management of pulmonary fibrosis often requires a lung biopsy to assess the unpredictable response of patients to glucocorticosteroids or other immune system suppressants. Lung transplants are sometimes an ultimate option in severe cases of pulmonary fibrosis and other lung diseases. Pulmonary fibrosis may also be caused by other specific diseases, such as sarcoidosis, a disease whose cause is unknown, that is characterized by the formation of granulomas or areas of inflammatory cells. The disease may attack any organ of the body, but most frequently attacks the lungs, and is generally diagnosed when a chest x-ray shows enlarged lymph glands in the center of both lungs or evidence of lung tissue thickening. For many sarcoidosis is a minor problem, and symptoms including dry cough, shortness of breath, mild chest pain, fatigue, weakness and weight loss-may appear infrequently and stop even without medication. For others, it is a serious, disabling disease that affects African-Americans more than members of any other race, although almost everybody may develop the disease, most common in young adults 20 to 40. Histiocytosis X, also associated with pulmonary fibrosis, seems to begin in the bronchioles or small airways of the lungs and their associated arteries and veins, and is generally followed by destruction of the bronchioles and narrowing and damaging of small blood vessels. It is diagnosed by a bronchoalveolar lavage test involving the removal and identification of cells from the lower respiratory tract. Symptoms of this disease include a dry cough (without sputum), breathlessness upon exertion, and/or chest pain. In approximately 50% of the cases, the disease is chronic with loss of lung function, and although glucocorticosteroid therapy is often prescribed, there is no evidence that it is effective. Many histiocytosis X sufferers are current or former cigarette smokers, although its association with smoking is not well understood. Many jobs, particularly those that involve mining or that expose workers to asbestos or metal dusts, may cause pulmonary fibrosis by inhalation of small particulate matter, e.g., dust or asbestos fibers that damage the lungs, especially the small airways and air sacs, and cause scarring (fibrosis). Agricultural workers are also affected by some particulate organic substances, such as moldy hay, which cause an allergic reaction in the lung called “Farmer's Lung”, and may cause pulmonary fibrosis as well. Asbestosis and silicosis are two occupational lung diseases whose causes are known. Asbestosis is caused by small needle-like particles of asbestos inhaled into the lungs, and cause lung scarring or pulmonary fibrosis that may lead to lung cancer. Silicosis is a dust disease that comes from breathing in free crystalline silica dust, and is produced by all types of mining in which the ore, e.g. gold, lead, zinc, copper, iron, anthracite (hard) coal, and some bituminous (soft) coal, are extracted from quartz rock. Workers in foundries, sandstone grinding, tunneling, sandblasting, concrete breaking, granite carving, and china manufacturing also encounter silica. Large silica particles are stopped in the upper airways, but the tiniest specks of silica are carried down to the lung alveoli, where they lead to pulmonary fibrosis. The use of glucocorticosteroids alone, or combined drug therapy, and the hope of lung transplant are three treatment approaches that are currently being tested, but up to the present time there is no good therapy for this disease. This patent provides the first effective therapy for these and other respiratory and lung ailments.
Cancer is one of the most prevalent and feared diseases of our times. It generally results from the carcinogenic transformation of normal cells of different epithelia. Two of the most damaging characteristics of carcinomas and other types of malignancies are their uncontrolled growth and their ability to create metastases in distant sites of the host, particularly a human host. It is usually these distant metastases that may cause serious consequences to the host since, frequently, the primary carcinoma is removed by surgery. The treatment of cancer presently relies on surgery, irradiation therapy and systemic therapies such as chemotherapy, different immunity-boosting medicines and procedures, hyperthermia and systemic, radioactively labeled monoclonal antibody treatment, immunotoxins and chemotherapeutic drugs.
Dehydroepiandrosterone (DHEA) is a naturally occurring steroid secreted by the adrenal cortex with apparent chemoprotective properties. Epidemiological studies have shown that low endogenous levels of DHEA correlate with increased risk of developing some forms of cancer, such as pre-menopausal breast cancer in women and bladder cancer in both sexes. The ability of DHEA and DHEA analogues, e.g. dehydroepiandrosterone sulfate (DHEA-S), to inhibit carcinogenesis is not clear but one suggestion is that it results from their non-competitive inhibition of the activity of the enzyme glucose 6-phosphate dehydrogenase (G6PDH). G6PDH is the rate limiting enzyme of the hexose monophosphate pathway, a major source of intracellular ribose-5-phosphate and NADPH. Ribose-5-phosphate is a necessary substrate for the synthesis of both ribo- and deoxyribonucleotides required for the synthesis of RNA and DNA. NADPH is a cofactor also involved in nucleic acid biosynthesis and the synthesis of hydroxmethylglutaryl Coenzyme A reductase (HMG CoA reductase). HMG CoA reductase is an unusual enzyme that requires two moles of NADPH for each mole of product, mevalonate, produced. Thus, it appears that HMG CoA reductase would be ultrasensitive to DHEA-mediated NADPH depletion, and that DHEA-treated cells would rapidly show the depletion of intracellular pools of mevalonate. Mevalonate is required for DNA synthesis, and DHEA arrests human cells in the G1 phase of the cell cycle in a manner closely resembling that of the direct HMG CoA. Because G6PDH produces mevalonic acid used in cellular processes such as protein isoprenylation and the synthesis of dolichol, a precursor for glycoprotein biosynthesis, DHEA inhibits carcinogenesis by depleting mevalonic acid and thereby inhibiting protein isoprenylation and glycoprotein synthesis. Mevalonate is a central precursor for the synthesis of cholesterol, as well as for the synthesis of a variety of non-sterol compounds involved in post-translational modification of proteins, such as farnesyl pyrophosphate and geranyl pyrophosphate. Mevalonate is also a central precursor for the synthesis of dolichol, a compound that is required for the synthesis of glycoproteins involved in cell-to-cell communication and cell structure. Mevalonate is also central to the manufacture of ubiquinone, an anti-oxidant with an established role in cellular respiration. It has long been known that patients receiving steroid hormones of adrenocortical origin at pharmacologically appropriate doses show increased incidence of infectious disease.
DHEA, also known as (3β)-3-hydroxyandrost-5-en-17-one, or dehydroisoandrosterone, is a 17-ketosteroid which is quantitatively one of the major adrenocortical steroid hormones found in mammals. Although DHEA appears to serve as an intermediary in gonadal steroid synthesis, the primary physiological function of DHEA has not been fully understood. It has been known, however, that levels of this hormone begin to decline in the second decade of life, reaching 5% of the original level in the elderly. Clinically, DHEA has been used systemically and/or topically for treating patients suffering from psoriasis, gout, hyperlipemia, and it has been administered to post-coronary patients. In mammals, DHEA has been shown to have weight optimizing and anti-carcinogenic effects, and it has been used clinically in Europe in conjunction with estrogen as an agent to reverse menopausal symptoms and also has been used in the treatment of manic depression, schizophrenia, and Alzheimer's disease. DHEA has also been used clinically at 40 mg/kg/day in the treatment of advanced cancer and multiple sclerosis. Mild androgenic effects, hirsutism, and increased libido were the side effects observed. These side effects can be overcome by monitoring the dose and/or by using analogues. The subcutaneous or oral administration of DHEA to improve the host's response to infections is known, as is the use of a patch to deliver DHEA. DHEA is also known as a precursor in a metabolic pathway that ultimately leads to more powerful agents that increase immune response in mammals. That is, DHEA acts as a biphasic compound: it acts as an immuno-modulator when converted to androstenediol or androst-5-ene-3β,17β-diol (βAED), or androstenetriol or androst-5-ene-3β,7β,17β-triol (βAET). However, in vitro DHEA has certain lymphotoxic and suppressive effects on cell proliferation prior to its conversion to βAED and/or βAET. It is, therefore, believed that the superior immunity enhancing properties obtained by administration of DHEA result from its conversion to more active metabolites.
Adequate ubiquinone levels have been found to be essential for maintaining proper cardiac function, and the administration of exogenous ubiquinone has recently been shown to have beneficial effect in patients with chronic heart failure. Ubiquinone depletion has been observed in humans and animals treated with lovastatin, a direct HMG CoA reductase inhibitor. Such lovastatin-induced depletion of ubiquinone has been shown to lead to chronic heart failure, or to a shift from low heart failure into life-threatening high grade heart failure. DHEA, unlike lovastatin, inhibits HMG CoA reductase indirectly by inhibiting G6PDH and depleting NADPH, a required cofactor for HMG CoA reductase. However, DHEA's indirect inhibition of HMG CoA reductase suffices to deplete intracellular mevalonate, and may result in depletion of ubiquinone, and in chronic heart failure following long term usage.
Adenosine may constitute an important mediator in the lung for various diseases, including bronchial asthma, COPD, CF, RDS, rhinitis, pulmonary fibrosis, and others. Its potential role was suggested by the finding that asthmatics respond favorably to aerosolized adenosine with marked bronchoconstriction whereas normal individuals do not. An asthmatic rabbit animal model, the dust mite allergic rabbit model for human asthma, responded in a similar fashion to aerosolized adenosine with marked bronchoconstriction whereas non-asthmatic rabbits showed no response. More recent work with this animal model suggested that adenosine-induced bronchoconstriction and bronchial hyperresponsiveness in asthma may be mediated primarily through the stimulation of adenosine receptors. Adenosine has also been shown to cause adverse effects, including death, when administered therapeutically for other diseases and conditions in subjects with previously undiagnosed hyper reactive airways.
Adenosine is a purine that contributes to intermediary metabolism and participates in the regulation of physiological activity in a variety of mammalian tissues. Adenosine participates in many local regulatory mechanisms, such as those occurring in synapses in the central nervous system (CNS) and at neuroeffector junctions in the peripheral nervous system. In the CNS, adenosine inhibits the release of a variety of neurotransmitters, such as acetylcholine, noradrenaline, dopamine, serotonin, glutamate, and GABA; depresses neurotransmission; reduces neuronal firing to induce spinal analgesia and possesses anxiolytic properties. In the heart, adenosine suppresses pacemaker activity, slows AV conduction, possesses antiarrhythmic and arrhythmogenic effects, modulates autonomic control and triggers the synthesis and release of prostaglandins. In addition, adenosine has potent vasodilatory effects and modulates vascular tone. Adenosine is currently being used clinically for the treatment of super ventricular tachycardia and other cardia anomalies. Adenosine analogues also are being investigated for use as anticonvulsant, anxiolytic and neuro protective agents. Adenosine has also been implicated as a primary determinant underlying the symptoms of bronchial asthma and other respiratory diseases, the induction of bronchoconstriction and the contraction of airway smooth muscle. Moreover, adenosine causes bronchoconstriction in asthmatics but not in non-asthmatics. Other data suggest the possibility that adenosine receptors may also be involved in allergic and inflammatory responses by reducing the hyperactivity of the central dopaminergic system. It has been postulated that the modulation of signal transduction at the surface of inflammatory cells influences acute inflammation. Adenosine is said to inhibit the production of super-oxide by stimulated neutrophils.
Clearly, there exists a well defined need for novel and effective therapies for treating COPD and other respiratory and lung ailments that cannot presently be treated, or at least for which no therapies are available that are effective and devoid of significant detrimental side effects. This is the case of ailments afflicting the respiratory tract, and more particularly the lung and the lung airways, including respiratory problems, bronchoconstriction, lung inflammation and allergies, depletion or hyposecretion of surfactant, etc. Moreover, there is a definite need for treatments that have prophylactic and therapeutic applications, and require low amounts of active agents, which makes them both less costly and less prone to detrimental side effects. Furthermore, it is readily apparent that the administration of a non-glucocorticoid steroid and/or ubiquinone or their respective salts, is useful for the treatment of respiratory, lung and malignant diseases such as bronchoconstriction, decreased or depleted lung surfactant, asthma, RDS, ARDS, rhinitis, chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), dyspnea, emphysema, pulmonary hypertension, pulmonary fibrosis, hyper-responsive airways, particularly conditions associated with infectious diseases, lung allergies and inflammation, neoplastic diseases such as lung cancer, and the like.
U.S. Pat. No. 5,527,789 discloses a method of combating cancer in a subject by administering to the subject dehydroepiandrosterone (DHEA) or DHEA-related compound, and ubiquinone to combat heart failure induced by the DHEA or DHEA-related compound. U.S. Pat. No. 6,087,351 discloses an in vivo method of reducing or depleting adenosine in a subject's tissue by administering to the subject dehydroepiandrosterone (DHEA) or DHEA-related compound. However, these patents do not teach using DHEA or DHEA-related compounds to prevent or treat COPD.